1. Field of the Invention
The present invention relates to a document reading apparatus that reads a document on which a transparent toner image is formed.
2. Description of the Related Art
Japanese Patent Application Laid-Open No. 5-265287 and Japanese Patent Application Laid-Open No. 2007-034040 discuss a copying machine employing an electrophotographic method which forms a glossy image using transparent toner. Japanese Patent Application Laid-Open No. 5-265287 discusses a copying machine which determines a non-character area in an image of a read document and forms an image with respect to the non-character area using transparent toner. Further, Japanese Patent Application Laid-Open No. 2007-034040 discusses a copying machine which analyzes a read document image such as a presentation material. The copying machine then forms an image using transparent toner only in an area containing a photographic image and not in an area containing graphs and drawings. The above-described copying machines thus form images using transparent toner in areas which require gloss according to the features of the document image.
However, when the above-described copying machines copy a document including both a glossy portion formed of the transparent toner and a non-glossy portion not formed of the transparent toner, the copying machines cannot copy the glossy portion as the glossy portion and the non-glossy portion as the non-glossy portion. To realize such copying, it is necessary for the copying machine to read the document on which a transparent toner image is formed and to extract the transparent toner image on the document to be read.